https://aceld.gitbooks.io/libevent/content/25hong_fa_mo_5f0f_md.html
github
这url 干活比较好
https://github.com/sysublackbear/libevent_source_study/blob/master/source_insight/libevent_14.md
文档
https://blog.csdn.net/zhouyongku/article/details/53431597